6. API E5 (1)

Environmental Guidance Document: Waste Management in Exploration and Production Operations

API E5 SECOND EDITION, FEBRUARY 1997

Strategies for Todays Environmental Partnership

American Petroleum Institute

Copyright American Petroleum Institute Provided by IHS under license with API Licensee=PETREVEN/5969924001, User=Figuera, Guillermo

Not for Resale, 11/26/2007 05:07:27 MSTNo reproduction or networking permitted without license from IHS

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One of the most significant long-term trends affecting the future vitality of the petroleum industry is the publics concerns about the environment. Recognizing this trend, API member companies have developed a positive, forward looking strategy called STEP: Strategies for Todays Environmental Partnership. This program aims to address public concerns by improving industrys environmental, health and safety performance; documenting performance improvements; and communicating them to the public. The foundation of STEP is the API Environmental Mission and Guiding Environmental Principles. API standards, by promoting the use of sound engineering and operational practices, are an important means of implementing APIs STEP program.

API ENVIRONMENTAL MISSION AND GUIDING ENVIRONMENTAL PRINCIPLES

The members of the American Petroleum Institute are dedicated to continuous efforts to improve the compatibility of our operations with the environment while economically developing energy resources and supplying high quality products and services to consumers. The members recognize the importance of efficiently meeting societys needs and our responsibility to work with the public, the government, and others to develop and to use natural resources in an environmentally sound manner while protecting the health and safety of our employees and the public. To meet these responsibilities, API members pledge to manage our businesses according to these principles:

0 To recognize and to respond to community concerns about our raw materials, products and operations.

o To operate our plants and facilities, and to handle our raw materials and products in a manner that protects the environment, and the safety and health of our employees and the public.

o To make safety, health and environmental considerations a priority in our planning, and our development of new products and processes.

o To advise promptly appropriate officials, employees, customers and the public of information on significant industry-related safety, health and environmental hazards, and to recommend protective measures.

o To counsel customers, transporters and others in the safe use, transportation and disposal of our raw materials, products and waste materials.

o To economically develop and produce natural resources and to conserve those resources by using energy efficiently.

o To extend knowledge by conducting or supporting research on the safety, health and environmental effects of our raw materials, products, processes and waste materials.

0 To commit to reduce overall emissions and waste generation.

o To work with others to resolve problems created by handling and disposal of hazardous substances from our operations.

o To participate with government and others in creating responsible laws, regulations and standards to safeguard the community, workplace and environment.

0 To promote these principles and practices by sharing experiences and offering assistance to others who produce, handle, use, transport or dispose of similar raw materials, petroleum products and wastes.



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Environmental Guidance Document: Waste Management in Exploration and Production Operations

Exploration and Production Department

API E5 SECOND EDITION, FEBRUARY 1997

American Petroleum Institute



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SPECIAL NOTES

API publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed.

API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations under local, state, or federal laws.

Information concerning safety and health risks and proper precautions with respect to particular materials and conditions should be obtained from the employer, the manufacturer or supplier of that material, or the material safety data sheet.

Nothing contained in any API publication is to be construed as granting any right, by im- plication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.

Generally, API guidance documents are reviewed and revised, reaffirmed, or withdrawn at least every five years. Sometimes a one-time extension of up to two years will be added to this review cycle. This publication will no longer be in effect five years after its publication date as an operative API guidance document or, where an extension has been granted, upon republication. Status of the publication can be ascertained from the API Authoring De- partment [telephone (202) 682-8000]. A catalog of API publications and materials is pub- lished annually and updated quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005.

All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording or other-

wise, without prior written permission from the publishel: Contact the Publishel; API Publishing Services, 1220 L Street, N. W , Washington, D. C. 20005.

Copyright O 1997 American Petroleum Institute



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FOREWORD This document reflects our industrys continuing commitment to environmental protec-

tion. It provides guidance for minimizing the direct and indirect environmental impacts of solid wastes originating from typical exploration and production (E&P) activities, which include exploration, drilling, well completions and workovers, field production, and gas plant operation.

This manual was prepared by the API Production Waste Issues Group, under the juris- diction of the API Exploration and Production Department Executive Committee on Envi- ronmental Conservation.

The oil and gas industry must operate where oil and gas deposits are found. This means that the exploration and production activities listed above will be conducted in a variety of ecosystems, whose sensitivity to the activities of man will vary widely. The oil and gas industry must be environmental stewards in two critical ways:

a. It must use environmentally sound operating practices to manage materials, land, and the waste generated from exploration and production activities. b. It must produce oil and gas reserves as efficiently and prudently as possible in order to prevent squandering critical natural resources.

API publications may be used by anyone desiring to do so. Every effort has been made by the institute to assure the accuracy and reliability of the data contained in them; however, the institute makes no representation, warranty, or guarantee in connection with this publication an hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may conflict.

Suggested revisions are invited and should be submitted to the director of the Exploration and Production Department, American Petroleum Institute, 1220 L Street, N.W., Washing- ton, D.C. 20005.



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1 1.1 1.2 1.3 1.4 1.5

2 2.1 2.2 2.3 2.4 2.5

3

3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7

4.8 4.9

CONTENTS

page

POLLUTION PREVENTION Introduction ................................................................................................................ 1 APIs Management Practice for Pollution Prevention ................................................ 1 Media ......................................................................................................................... 1 Understanding Operational Impacts ........................................................................... 3 Pollution Prevention and waste Minimization ........................................................... 3

WASTE MANAGEMENT SYSTEM Introduction ................................................................................................................ 4 Summary of a Ten-Step Plan for Waste Management ................................................ 4 Training ...................................................................................................................... 4 Waste Tracking ........................................................................................................... 5 Auditing ...................................................................................................................... 5

WASTE GENERATION IN EXPLORATION AND PRODUCTION OPERATIONS Introduction ................................................................................................................ 6 Exploration ................................................................................................................. 6 Drilling ....................................................................................................................... 7 Completion and Workover ......................................................................................... 9 Field Production ....................................................................................................... 10 Gas Plant Operations ................................................................................................ 14 Transportation Pipelines ........................................................................................... 16 Offshore Operations ................................................................................................. 17

ENVIRONMENTAL LEGISLATION AND REGULATIONS Introduction .............................................................................................................. 17 The Resource Conservation and Recovery Act (RCRA) ......................................... 17 The Safe Drinking Water Act (SDWA) .................................................................... 22 The Clean Water Act (CWA) .................................................................................... 23 The Clean Air Act (CAA) ........................................................................................ 25 The Toxic Substances Control Act (TSCA) ............................................................. 25 The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) .......................................................................................... 25 The Oil Pollution Act of 1990 (OPA 90) ................................................................. 27 Other Federal Acts .................................................................................................. 27

4.10 Other Regulations and Agreements ......................................................................... 29

5 5.1 5.2 5.3 5.4 5.5

6 6.1 6.2 6.3 6.4

WASTE MANAGEMENT METHODS Introduction .............................................................................................................. 29 Source Reduction .................................................................................................... 29 Recycling and Reclaiming ........................................................................................ 30 Treatment .................................................................................................................. 30 Disposal .................................................................................................................... 30

IDENTIFYING MANAGEMENT OPTIONS FOR SPECIFIC WASTES Introduction .............................................................................................................. 38 Produced Water ........................................................................................................ 39 Drilling Wastes ......................................................................................................... 39 Workover and Completion Wastes ........................................................................... 41

V



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5 Tank Bottoms. Emulsions. Heavy Hydrocarbons. and Produced Solids .................. 42 6.6 Contaminated Soil .................................................................................................... 43 6.7 Used Oils and Solvents ............................................................................................. 43 6.8 Dehydration and Sweetening Waste ......................................................................... 44 6.9 Oily Debris and Filter Media ................................................................................... 44 6.10 Gas Plant Process and Sulfur Recovery Waste ......................................................... 45 6.1 1 Cooling Tower Blowdown. Boiler Water. Scrubber Liquids. and

Steam Generator Wastes ........................................................................................... 45 6.12 Downhole and Equipment Scale .............................................................................. 45 6.13 StormwaterRigwash ................................................................................................ 45 6.14 Unused Treatment Chemicals .................................................................................. 46 6.15 Asbestos .................................................................................................................. 46 6.16 Used Batteries .......................................................................................................... 46 6.17 PCB Transformer Oil ............................................................................................... 46 6.18 NonPCB Transformer Oil ........................................................................................ 46 6.19 Empty Oil and Chemical Drums ............................................................................. 47 6.20 Naturally Occurring Radioactive Material ............................................................... 47 6.21 Geological and Geophysical Operation Wastes ....................................................... 47 6.22 Recompression and Facility Utility Wastes .............................................................. 47

APPENDIX A-Guidelines for Developing Area-Specific Waste

APPENDIX B-Waste Management Planning Aids ........................................................ 55

APPENDIX D-Summary of Environmental Legislation and Regulations ..................... 61 APPENDIX E-Acronyms ............................................................................................... 63

APPENDIX G-EPA Publication: (EPA 530-K-95-003), May 1995- Crude Oil and

Management Plans ................................................................................ 49

APPENDIX C-Summary Waste Table ........................................................................... 57

APPENDIX F-Reference Materials ............................................................................... 67

Natural Gas Exploration and Production Wastes: Exemption from RCRA Subtitle C Regulation ................................................................ 69

Figures 1-Media Pathways ......................................................................................................... 2

Tables 1-Ten-Step Plan Summary ............................................................................................ 5 2-Overview of Waste Management Methods .............................................................. 30 3-API Metals Guidance: Maximum Soil Concentrations ........................................... 33 &Example of E&P Waste. Disposal Technique. and

Applicable Constituent Criteria ............................................................................... 34 A- 1-Ten-Step Plan for Preparing a Waste Management Plan .................................... 49 B-1-Iron Sulfide Scale and Iron Sponge ..................................................................... 56

D-1Summq of Key Legislation and Regulations ................................................... 61 C- I-Summary Waste Table ......................................................................................... 57

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Waste Management in Exploration and Production Operations

1 Pollution Prevention

1.1 INTRODUCTION

Pollution prevention is the practice of reducing or elimi- nating pollutant discharges to air, water, or land. It includes the development of more environmentally acceptable products, changes in processes and practices, source reduction, beneficial use, environmentally sound recycling, waste minimization, proper waste handling, waste treatment, and proper disposal practices. This section presents an overview of media, operational impacts, and waste minimization methods, including the EPA hierarchy of waste management. These basic concepts are critical in achieving pollution prevention goals.

Pollution prevention requires continuous improvement in operating practices. Industry should review its use of materials, processes, practices, and products in order to identify ways to reduce or eliminate pollution. A practical approach encourages the use or production of environmentally acceptable products while working toward source reduction on the following waste management hierarchy:

source reduction (most preferred)

recyclinglreuse

treatment, and/or

land disposal (least preferred) I

Details are presented in 1.3.2.

The API Pollution Prevention Management Practices for APIs Strategies for Todays Environmental Partnerships (STEP) program embody the petroleum industrys practical commitment to pollution prevention. They provide specific guidelines for compliance with these Guiding Environmental Principles, which are as follows:

a. To recognize and to respond to community concerns about our raw materials, products, and operations. b. To operate our plants and facilities, and to handle our raw materials and products in a manner that protects the environment and the safety and health of our employees and the public. c. To make safety, health, and environmental considerations a priority in our planning, use, and development of new products and processes. d. To advise promptly appropriate officials, employees, customers, and the public of information on significant industry- related safety, health, and environmental hazards and to recommend protective measures. e. To counsel customers, transporters, and others in the safe use, transportation, and disposal of our raw materials, products, and waste materials.

f. To develop and produce natural resources economically and to conserve those resources by using energy efficiently. g. To extend knowledge by conducting or supporting research on the safety, health, and environmental effects of our raw materials, products, processes, and waste materials. h. To commit to reduce overall emissions and waste generation. i. To work with others to resolve problems created by handling and disposal of hazardous substances from our operations. j . To participate with government and others in creating responsible laws, regulations, and standards to safeguard the community, workplace, and environment. k. To promote these principles and practices by sharing experiences and offering assistance to others who produce, handle, use, transport, or dispose of similar raw materials, petroleum products, and wastes.

1.2 APIS MANAGEMENT PRACTICE FOR POLLUTION PREVENTION

Both management commitment and comprehensive planning are critical to a successful pollution prevention program. Steps to consider in developing and operating such a program include the following:

a. Providing management support for ongoing pollution prevention activities through appropriate policies, actions, com- munications, and resource commitments. b. Developing and implementing a program to improve prevention and early detection and reduce impacts of spills of crude oil and petroleum products and other accidental releases from operations. c. Developing an inventory of significant releases to air, water, and land; identifying their sources; and evaluating their impact on human health and the environment. d. Periodically reviewing and identifying pollution prevention options and opportunities, developing approaches for reducing releases, and setting goals and schedules for reducing releases and measuring progress; consider the issues of community concerns, technology and economics, and impact on human health and the environment. e. Including pollution prevention objectives in research efforts and in the design of new or modified operations, processes, and products. f. Supporting an outreach program to promote pollution prevention opportunities within the industry, including sharing of industry experiences and accomplishments.

1.3 MEDIA

Proper management of wastes is important to the protection of human health and the environment. Waste can be transported via three natural carriers-water, soil, and air.

1



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2 API E5

All three media may provide pathways by which potentially polluting materials can migrate from their original source. Thus, materials used and wastes generated in exploration and production operations should be managed by considering risk to human health and the environment via media pathways (see Figure 1).

1.3.1 Water

Fresh water for human consumption, domestic needs, recreation, stock water, irrigation of crops, and industry comes from underground aquifers, lakes, streams, and reservoirs.

Materials from spills or improper waste disposal may con- taminate aquifers. Of major concern are those aquifers that contain water suitable for drinking. Also important are aquifers used for agricultural purposes. Pollutants found in water are measured in concentrations of parts per billion (ppb); some of these pollutants may cause that water to fail drinking water standards.

The quality of aquifer waters can be degraded by pollutants to such a degree that it is not practical to restore the aquifer to drinking water standards.

1.3.2 Soil

Most fresh water is stored in underground reservoirs Spills can adversely affect the capacity of soil to support called aquifers. Aquifers are part of a large water-recycling agricultural, industrial, human, and recreational uses. Soil system as illustrated in Figure 1. These porous formations or acts to retain spilled, improperly stored, or disposed materi- sediments can store and transport groundwater from rain, als; however, once in the soil, pollutants can migrate to air leakage of stream beds, and other sources. and water and be picked up by plants and animals. Contam-

Evaporation and transpiration from

bgd = billion gallons per day

Figure 1-Basic Media of Soil, Air, and Water Can Transport Pollutants Away From Their Original Source



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WASTE MANAGEMENT IN EXPLORATION AND PRODUCTION OPERATIONS 3

inants can evaporate into the atmosphere, be carried by rain- generated by the general public and can be managed simi- water to a lake, creek, or other surface water, and be leached larly. Most of the waste generated by the oil and gas industry downward into groundwater. consists of naturally occurring materials brought to the sur-

1.3.3 Air Due to large increases in costs of waste management, in- face in association with extracted oil and gas.

Gaseous waste released to the air can potentially affect hu- mans, animals, and plant life through inhalation or dermal contact. Indirectly, gaseous wastes may alter the chemical balance in the atmosphere. Acid rain is a known result of al- tering the chemical makeup of the atmosphere. Ozone deple- tion and global warming are thought by some to be the result of human impact on the atmosphere.

1.3.4 Summary

A properly implemented pollution prevention program can reduce or eliminate pollutant discharges to air, water, or land. API supports cooperative efforts to research and develop scientifically based standards and promotes technical advancements for the evaluation and implementation of measures to address environmental impacts.

1.4 UNDERSTANDING OPERATIONAL IMPACTS

Because exploration and production (E&P) operations can affect all environmental media, API suggests the use of sound science to identify adverse impacts and the means to mitigate, reduce, or eliminate them. Science is also critical to developing cost-effective strategies that address environmental risks. Science provides the foundation for identifying methods to prevent or reduce pollution, for expanding waste management options to reduce risk, and for developing and improving pollution control technologies.

Sound science is the key to determining which environmental problems pose the greatest risk to human health, ecosystems, and the economy. Without sound scientific information, high profile but low risk problems may pos- sibly be targeted, while more significant threats remain ignored.

A sound scientific understanding of environmental risks to populations and ecosystems will help create a more effective allocation of resources-resources which can be targeted towards hazards that pose the greatest environmental risk.

1.5 POLLUTION PREVENTION AND WASTE MINIMIZATION

Waste minimization is a major component of pollution prevention. The goals of a waste minimization plan are to reduce the total volume or quantity of waste generated and to reduce the toxicity of waste.

Hydrocarbon recovery, an extractive procedure, inherently generates wastes. Some of these wastes are similar to those

creasing complexity of waste management regulations, and efforts to reduce potential environmental liabilities, many API member companies have implemented in-house waste minimization programs.

These programs go beyond traditional approaches to waste management and incorporate pollution prevention concepts.

1.5.1 Solid Waste Definition

According to federal regulations, a solid waste is any material that is discarded or intended to be discarded. Solid wastes may be either solid, semi-solid, liquid, or contained gaseous material. Point source water discharges, subject to federal permits under the Clean Water Act, are not considered solid wastes.

1.5.2 EPA Hierarchy of Methods

EPA has developed the following hierarchy of waste management methods to guide generations toward waste minimization. The four waste management hierarchy steps, in decreasing order of preference are as follows:

a. Source Reduction-reduce the amount of waste at the source through the following:

material elimination inventory control and management material substitution process modification improved housekeeping return of unused material to supplier

b. Recycling/Reuse-reuse and recycle material for the original or some other purpose, such as materials recovery or energy production; this may occur onsite or offsite, through the following methods:

reuse reprocess reclaim use as fuel underground injection for enhanced recovery roadspreading

c. Treatment-destroy, detoxify, and neutralize wastes into less harmful substances through the following methods:

filtration chemical treatment biological treatment thermal treatment extraction



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chemical stabilization incineration landfarming landspreading

d. Disposal-dispose of wastes through the following methods:

landfills NPDES discharge solidification burial underground injection for disposal

1.5.3 Summary

By incorporating waste minimization practices into the waste management program, the generator may further efforts to

a. Protect public health and worker health and safety. b. Protect the environment. c. Meet company, state, and/or national waste minimization goals. d. Save money by reducing waste treatment and disposal costs and other operating costs. e. Reduce potential environmental liabilities.

2 Waste Management System

2.1 INTRODUCTION

In order to achieve pollution prevention and waste minimization goals, waste management needs to be viewed as an integrated system. A good waste management system should include the following key elements:

a. A system for maintaining knowledge of pertinent laws and regulations. b. A system for pollution preventiodwaste minimization. c. A health and safety program. d. An incident response preparedness program. e. A training program. f. A system for proper waste identification. g. A transportation program. h. A proper waste storage and disposal program. i. A system for waste tracking, inventories, and record- keeping. j. A waste management auditing program.

This section introduces the concept of a waste management plan-the tool for implementing these key elements at the field level, where actual waste management decisions should be made.

The key elements of training, waste tracking, and auditing are also discussed.

2.2 SUMMARY OF A TEN-STEP PLAN FOR WASTE MANAGEMENT

A waste management plan should

a. Offer a solid waste plan that is area-specific. b. Provide proper management guidance for each waste generated in E&P operations. c. Be written for field operations. d. Be used to ensure regulatory compliance and environmentally sound management of wastes. e. Form a basis for training, evaluation, monitoring, and pollution prevention programs. f. Be periodically reviewed and updated as new practices and options are discovered.

API suggests the ten-step waste management plan shown in Table 1 for integrating the waste management system into operations. This plan is described in detail in Appendix A. It has proven successful for a number of member companies. Appendix B includes planning aids to help in preparing the waste management plan.

Both technology and regulatory requirements in the environmental field are changing constantly. For these reasons, open communication among field operations personnel, environmental and legal specialists, and management is crucial to conducting environmentally sound operations.

2.3 TRAINING

Training in the proper identification and handling of waste material is vital in any exploration or production operation. Field personnel and management should be trained in environmentally sound and safe waste management practices. In- struction in waste management should include the following:

a. General environmental awareness. b. Health and safety concerns related to waste handling. c. Benefits of proper waste management, including risk reduction for future liabilities. d. Review of internal environmental policies and other doc- umentation of management support. e. Environmental laws and regulations. f. Legal liability, both corporate and personal, associated with improper handling of waste. g. The applicable facility waste management program.

In addition, a company may consider scheduling periodic training to cover updates of procedures, review of incidents, and feedback from field personnel.

Federal agencies also mandate personnel training as follows:

a. The U.S. Occupational Safety and Health Administration (OSHA) requires specific, detailed training for certain operations that may be associated with waste management. b. Emergency response to a release of hazardous chemicals



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(including crude oil) and the following cleanup operations may require certified and trained personnel (HAZWOPER-29 Code of Federal Regulations Part 1910.120). c. OSHA also has training and information requirements for personnel who might be exposed to hazardous chemicals (HAZCOM-29 Code of Federal Regulations Part 1910.1200). d. The EPA requires annual training for certain hazardous waste generators (40 Code of Federal Regulations Part 262.34). e. State agencies may have additional health, safety, and waste management requirements. f. The U.S. Department of Transportation (DOT) and some state agencies have transportation requirements for certain wastes. Specific training is required for employees handling hazardous materials (49 Code of Federal Regulations Part 172.702).

Training can be done in-house or through enrollment in schools, workshops, seminars, and conferences available to industry and the general public. Many training opportunities are available through academic institutions or private companies.

2.4 WASTE TRACKING

To ensure proper waste disposal and to minimize individual company liability for the cleanup of improperly disposed waste, it is important to know the types and amounts of waste generated, as well as the ultimate disposition of that waste.

This should be documented by using a company waste tracking system.

Sound waste management techniques should include tracking for both onsite and offsite disposal.

Identification of types and amounts of waste generated ben-

efits operations by allowing identification of waste minimization opportunities. Tracking wastes offsite helps prevent significant costs associated with improper waste disposal.

2.5 AUDITING

Companies should consider developing audit programs for their own facilities as well as third-party facilities that may accept their wastes.

2.5.1 Company Facilities

An onsite waste management auditing program assesses the compliance status of a companys facilities and programs for waste management. An auditing programs goal is to help companies achieve higher levels of environmental performance.

Penalties for noncompliance are harsh. Failure to comply with laws and regulations regarding waste management can subject a company to loss of business opportunities, as well as to civil and criminal penalties. Noncompliance can also subject directors, officers, and employees to fines, criminal penalties, and imprisonment.

One of the benefits of a waste management audit program is that company management is provided with information on waste management practices. Other potential benefits include the following:

a. Improved compliance records and reduction of fines, legal actions, and incidents or accidents. b. Improved communication between all levels of company management. c. Improved financial planning efficiency by reducing civil and criminal exposure, enhancing evidence of insurability, im-

Table 1-Ten-Step Plan Summary

Step I .

Step 2.

Step 3.

Step 4.

Step 5.

Step 6.

Step 7.

Step 8.

Step 9.

Step 10.

Management approvd-obtain management approval and support.

Area definitiondefine operating area such as oil field, unit. lease, or state.

Waste identification-identify each waste generated within Step 2 area and briefly describe each waste.

Regulatory analysis-complete reviews of relevant federal, state, and local laws on waste types for which requirements exist; also review lease agreements and landowner agreements.

Waste classification-categorize each identified waste; determine whether it is exempt or nonexempt and nonhazardous or hazardous.

Waste minimization-review processes that generate the waste and execute procedures to reduce waste generation.

List and evaluate waste management and disposal options-list the potential options for each waste and rank their desirability.

Select preferred waste management practice(s)-select a waste management option for each waste and the best practice for each operation location.

Prepare and implement an area-specific waste management plan-develop and implement this by compiling a11 options into a plan. Summarize in documents.

Review and update waste management plan-Define a review and update procedure.



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proving public relations, and reducing barriers to successful Decision criteria that will rate a commercial facility as ei- acquisitions and merger negotiations. ther acceptable or unacceptable, based on the collected site in-

Refer to the API document Envimnmental Audit Guideline Protocol and Checklist for help in designing an environmental audit format customized to meet the specific criteria of your facility or compliance program. This guideline was developed by API specifically for the oil and gas E&P industry.

2.5.2 Offsite Noncompany Facilities

An integral part of a waste management program should be a system or process to assess whether commercial waste disposal facilities-including reclaiming and recycling facilities to which wastes are sent-operate in an environmentally and financially sound manner. It is imperative to select commercial facilities that manage wastes properly, inclusive of recycling, treatment or neutralization, and disposal. Companies should consider auditing commercial facilities to limit potential exposure to future environmental liability that might result from improper management by the commercial facility.

Commercial disposal site audits should consider the following:

a. The regulatory aspects of a facility, including: l . Proper permits. 2. Compliance with permits. 3. Relationship with regulatory agencies. 4. History of violations. 5 . Remediation projects in progress. 6. Closure plans. 7. Insurance or other surety bonds. S. Manifesting records and procedures.

b. The operational aspects of a facility, including: l . Adequacy of onsite waste treatment equipment. 2. Adequacy of disposal or recycling processes. 3. Location of the disposal of secondary waste streams that the facility is permitted to manage. 4. Site security. 5. Adequacy of lab analysis. 6. Incoming waste testing and verification procedures. 7. Secondary containment and spill prevention. S. Adequate waste storage prior to disposal. 9. Housekeeping. 10. Adequate contingency plans and training. 1 l . Environmental expertise and financial standing.

c. Physical aspects, including: l . Depth to groundwater. 2. Monitoring well data. 3. Soil data. 4. Geology. 5. Hydrogeology. 6. Remoteness of site location and public exposure potential.

formation, should be established.

or recycling.

that acceptable sites continue to operate acceptably.

Unacceptable sites should not be utilized for waste disposal

Site reevaluation on a periodic basis is critical to ensuring

3 Waste Generation in Exploration and Production Operations

3.1 INTRODUCTION

Wastes are generated in each phase of E&P operations. This section summarizes wastes generated in each phase and the associated environmental impact considerations. The work phases are as follows:

a. Exploration. b. Drilling. c. Completion and workover. d. Field production. e. Gas plant operations. f. Transportation. g. Offshore operations.

See Appendix C for a summary of E&P waste sources.

3.2 EXPLORATION

Exploration operations identify locations that contain potential oil and gas deposits. These operations may begin with remote sensing and aerial geomagnetic surveys to identify underground geologic structures where oil and gas may have ac- cumulated. Seismic surveys and related geologic field work are conducted on potential locations.

3.2.1 Seismic Surveys

Prior to drilling an exploratory well, seismic surveys and related geologic field work are the primary exploration activities that generate appreciable amounts of waste. Three basic field work activities contribute to waste generation:

a. Access to the area of interest. b. Construction of seismic lines. c. Construction and maintenance of a base camp or camp sites.

The environmental impact of each of these efforts should be considered.

3.2.1.1 Accessing Areas of Potential Deposits

Gaining access to an area of potential oil and gas deposits often requires construction of roads or footpaths into remote areas. Construction may involve clearing trees and brush and



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temporary displacement of topsoil'. Good management processes include the following:

a. Using cleared foliage in soil conservation and control. b. Retaining and replacing topsoil. c. Encouraging revegetation by native flora.

3.2.1.2 Seismic Line Construction

Seismic lines are constructed by clearing a 3- to 6-foot- wide footpath. The root stock and topsoil should be left in place. Shallow holes are typically drilled along the seismic line and explosives are placed in them to be detonted. Any unused shot holes and/or craters caused by explosions should be backfilled to reduce the chance of subsequent erosion. An alternative is to use vehicle-mounted, nonexplosive energy sources.

Wastes generated during this operation include explosives residue, used oil and filters, line stakes or markers, and domestic waste. In general, the volume and toxicity of these wastes are minimal; however, steps should be taken to assure that all nonrecyclable material is either (a) incinerated or buried onsite when allowed by applicable regulations; (b) collected and carried out by the seismic crew once operations cease; or (c) otherwise appropriately managed.

3.2.1.3 Base Camp

Seismic exploration and geologic field work may require a large workforce. In remote areas, a base camp to accom- modate personnel and equipment is sometimes necessary. Base camp operations may generate many different wastes.

Base camps are typically self-contained. They will usually consist of personnel accommodations, dining facilities, vehicle/aircraft fueling facilities, and maintenancelparking areas for vehicles and helicopters. Wastes generated include sewage effluent, domestic refuse, used oil and filters, empty petroleum hydrocarbon storage containers, and building material wastes. Disposal of these wastes can be a common problem for base camps in areas where water treatment and waste disposal facilities do not exist. In such cases, provi- sions must be made for proper treatment or disposal. Specific steps to treatment and disposal include the following:

a. All food wastes and other putrefiable material should be collected and properly disposed. b. Solid and hydrocarbon wastes should be evaluated for recycling whenever possible. c. Residue from burned or incinerated wastes should be buried or transported offsite. d. A system for the collection of sewage and water effluents should be constructed and designed to flow through a soak- away system of permeable, earth-covered beds in such a way as to not impact potable water supplies. e. Wastes requiring special handling such as used oil and filters should be kept segregated and disposed in a manner

that prevents surface water or groundwater contamination. f. All material, equipment, and man-made structures (such as buildings, bridges, helipads, and so forth) should be dis- mantled and removed from the area when work is completed, unless otherwise agreed upon by the landowner and the operators.

The disposal of solid and liquid wastes is controlled by regulation. Landowner consent and/or permits from appropriate authorities may be required before waste disposal methods such as incineration or construction of effluent field can be utilized.

3.2.2 Waste Summary

A list of the major waste categories that may be generated during exploration operations is shown below. See Appendix C for a more complete listing of wastes generated by E&P.

Exploration Operations Wastes

Absorbent material

Antifreeze

Batteries

Domestic refuse

Domestic wastewater

Filters First-aid waste

Hydraulic fluid Incineration ash

Mudkuttings from shot holes

Paint related materials

Rags, oily

Sanitary wastewater

Scrap metal

Soil, contaminated

Solvents, petroleum naphtha

Stormwater

Tires

Unused materials, discarded

Used oil Vegetation

Washdown water (rigwash)

Water, noncontact (for example, cooling or fire water)

Wood

3.3 DRILLING

Drilling operations are conducted to locate the oil and gas (that is, exploratory drilling), to delineate a discovered reserve or to develop a reservoir for production. The drilling operation has two key components, the drilling rig and the circulation system, which are discussed below.

3.3.1 Drilling Rig

3.3.1.1 Introduction

The drilling rig provides the power and equipment (including safety equipment and systems such as blowout pre- venters) necessary to drill the wellbore. Its key systems and their uses areas follows:

3.3.1.2 Hoisting System

The hoisting system lifts drill pipe in and out of the well and controls weight on the drill bit as it penetrates rock and



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sand formations. It also handles drill pipe when it is out of the wellbore and is used to run casing into the wellbore.

3.3.1.3 Rotating System

The rotating system turns the drill bit so that it can pene- trate underground rock and sand formations.

3.3.1.4 Casing

Casing serves the following functions:

a. It protects the integrity of the wellbore during drilling. b. It provides a conduit for fluid movement both up and down the wellbore. c. It keeps drilling fluids from leaving the wellbore and seeping into the formation. d. It allows fluids to flow to the surface for processing after well completion. e. It provides protection for underground sources of drinking water.

Wastes generated by the drilling rig result primarily from the operation and maintenance of rig equipment. These wastes include washwater (rigwash), used lubricating oils and filters, solvents, hydraulic fluids, gaskets, used drill bits and pipe, discarded thread protectors, cut drill line, empty grease and pipe dope containers, absorbent materials (such as clay and pads), worn brake pads, and similar materials.

kgwash, or water used to wash down the rig floor, may contain minor amounts of the detergents that are used to clean the rig and provide a safe work area. The system used to collect rigwash may also collect rainwater.

3.3.2 Circulating System


The circulating system is the lifeblood of the drilling operation. In this phase, the drilling fluid (that is, mud) is formulated and maintained; circulated downhole to cool the drill bit and flush drilled cuttings from the bottom of the wellbore; used to transport cuttings to the surface where they are mechanically removed from the mud system; and then returned to tanks where the process starts again.

3.3.2.2 Drilling Mud

The drilling mud, mostly water-based clays and inert weighting materials, is formulated using various additives, depending on expected well conditions. Additives help cool the drill bit, lubricate the drill string, and remove the drilled cuttings from the wellbore; they also add the necessary weight to prevent formation fluids from entering the wellbore and support and prevent damage to the underground formations being drilled. In certain geographic regions, spe-

cial drilling fluids such as oil- or saltwater-based muds are used when drilling deep, high-temperature, high-pressure, water-sensitive reservoirs, or high-angle wells.

Wastes generated during drilling mud formulation typically include empty additive containers (such as bags and pails) and unused or contaminated additives.

After formulation, drilling mud is stored in tanks before it is pumped down the drill string. As mud exits the drill bit nozzles, it cools the bit and flushes away any drilled cuttings and solids at the wellbore bottom. The mud then carries these drilled solids to the surface where they are removed using cleaners (such as hydrocyclones or desilters, centrifuges, and shale shakers). These wastes are typically collected in a reserve pit adjacent to the drilling rig.

Wastes generated during drilling operations may include the following:

a. Drilling fluids (muds) and solids. b. Cement returns. c. Saltwater. d. Oil. e. Formation cuttings (such as shale, lime, salt, and dolomite).

The waste volumes generated will vary greatly, depending on the well's diameter, depth, type of mud system, and other operating factors.

3.3.2.3 Reserve Pits

Unlined or lined reserve pits store supplies of water, waste drilling fluids, formation cuttings, rigwash, and stormwater runoff from the drilling location. Unlined pits are normally used for freshwater mud systems; lined pits are normally used for oil- or saltwater-based mud systems, or in areas of shallow groundwater, or in those adjacent to fresh surface waters.

Liners may not be necessary for some oil- or saltwater- based mud systems, such as where soil and hydrogeological conditions preclude any adverse impact, or soil, waste mud, and cuttings may be managed to ensure protection of soil and groundwater (for example, treated to fix or solidify contami- nants). Conversely, liners may be required in areas that are hy- drogeologically or otherwise sensitive. In specific cases, closed-loop drilling mud systems may be required to protect environmentally sensitive areas. These systems do not require reserve pits.

Regulations apply as follows:

a. State regulations usually require pit construction to comply with specified land use standards. b. State regulations normally restrict reserve pit usage to the drilling operation and require that pits be closed shortly after cessation of drilling operations (normally within 6-12 months). c. Certain reserve pits may remain open for extended periods because multiple wells may be drilled from a single well pad. Special regulations, including compliance with applicable wa-



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ter quality standards for reserve pit contents, may be required in environmentally sensitive areas.

3.3.3 Other Drilling Rig Operations

Support equipment located adjacent to the drilling rig is essential to the drilling operation. Equipment includes fuel tanks, electric power generators, pipe racks, and equipment used to support the maintenance of personnel quarters.

Wastes can include the following:

a. Used oil and filters. b. Contaminated fuel and spillage. c. Domestic waste and sanitary sewage. d. Solid waste (including paper sacks, cans, and drums). e. Quarters, garbage, and other materials.

3.3.4 Waste Summary

A list of the major waste categories that may be generated during drilling operations is shown below. See Appendix C for a more complete listing of wastes generated by E&P.

Drilling Operations Waste

Absorbent material Antifreeze Batteries

Blasting sandmaterial

Cement returns CompletionlW.O./well

treatment fluids Constructioddemolition debris

Domestic refuse Domestic wastewater

Drill cuttings

Drilling fluids

Filters first-aid waste

Hydraulic test (BOP) fluids

Hydraulic fluid Incineration ash

Insulation material

Mud sacks

Paint-related materials

Pallets

Polychlorinated biphenyls (PCBs) Produced sand

Produced water Radioactive waste, LSA [low

specific activity (for example, tracer materials)]

Rags, oily

Sanitary wastewater

Scrap metal

Soil, contaminated Solvents

Spill cleanup waste. hydrocarbon (for example, crude)

Stormwater

Thread protectors Tires


Used oil Vegetation


Water, noncontact (for example, cooling or fire water)

Wood

3.4 COMPLETION AND WORKOVER

Once drilling operations are finished, newly drilled wells must be completed before being put into production. There are many methods of completing or preparing a well for

production or injection.

a. Generally, the well casing must be'perforated to allow fluid flow. h. Downhole equipment may also be installed to facilitate production or injection. c. The producing formation may also be acidized or frac- tured to enhance production or injection capacity.

Workover rigs are typically used for completion activities; in some cases, drilling rigs are also used. The latter is not nor- mal practice, due to the higher operating cost of a drilling rig as compared to a workover rig. When using a drilling rig, larger quantities of waste may be generated due to the rig's increased size.

In addition, existing production and injection wells require periodic maintenance utilizing workover rigs. Workover operations include installing tubing and packer, acidizing or fracturing stimulations, replacing tubing or pumping equipment, recompleting to new reservoirs, or plugging and aban- doning of wellbores. The amount and type of waste generated from completion, well treatment, and workover operations can range from virtually none for chemical treatments and logging operations to large volumes similar to those encoun- tered during drilling operations.

Wastes generated from the workover rig itself include hydraulic fluids, used oils and filters, and other maintenance wastes. Other wastes include spent completion and workover fluids and filters (for example, diatomaceous earth), produced water, produced sand and other solids, spent acids, inhibitors, and solvents.

Spent or used fluids are normally produced through flow- lines to production facilities or trucked to operator-owned production facilities for further processing. Workover fluids are also disposed of at commercial facilities when operators are unable to process them in their own production facilities.

A list of the major waste categories that may be generated during completion and workover operations is shown below. See Appendix C for a more complete listing of wastes generated by E&P.

Completions and Workover Operations Waste

Absorbent material

Antifreeze

Batteries

Blasting sandhaterial

Cement returns

CompletionlW.O./well treatment fluids

Constructioddemolition debris

Pipdequipment hydrates

Pipe/equipment scale

Pit sludges

Polychlorinated biphenyls (PCBs)

Produced sand

Produced water

Radioactive waste, LSA (low specific activity [for example, tracer materials])



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~

STD.API/PETRO ES-ENGL L777 E 0732270 05b11684 T25

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Crude oilkondensate, waste

Domestic refuse

Domestic wastewater

Drill cuttings

Drilling fluids

Filters

First-aid waste

Hydraulic test (BOP) fluids

Hydraulic fluid

Incineration ash

Insulation material

Naturally occumng radioactive material (NORM)

Packing fluids

Paint-related materials

Pallets

Parafin

Rags, oily

Sanitary wastewater

Scrap metal

Soil. contaminated

Solvents

Source sand

Source water

Spill cleanup waste, hydrocarbon (for example, crude)

Stormwater

Tires


Used oil

Vegetation


Water, noncontact (for example, cooling or fire water

Wood

3.5 FIELD PRODUCTION

3.5.1 Introduction

After a well is drilled and completed, field facilities collect oil and/or gas from the well and prepare it for sale. Well fluids are often a complex mixture of liquid hydrocarbons, gas, water, and solids. The objective of the production process is to separate constituents of the mixture, remove those that are nonsaleable, and sell the liquid hydrocarbons and gas. Purchasers have contract standards for the oil and gas they will accept. For example, oil purchasers typically limit the amount of basic sediment and water (BS&W) to less than 1 percent. Gas purchasers set similar limits on water, water vapor, hydrogen sulfide (H2S), carbon dioxide (CO,), and BTU content.

The field production facility can be grouped into the following areas:

a. Wells and gathering systems. b. Oil and produced water treatment systems. c. Dehydration and sweetening. d. Injection operations. e. Oil storage and sales. f. Compression and gas sales. g. Other field production facilities and operations.

The following sections describe each field facility area and the wastes that may be generated from it in the production process.

3.5.2 Wells and Gathering Systems


Wastes generated at the well site include paraffin, oil and produced water contaminated soils, and used gear box lubrication oil. These wastes are more commonly found at oil wells than at gas wells.

3.5.2.2 Paraffin Removal

Paraffin precipitates within tubing and piping when oil containing parafin is produced up a wellbore and pressures and temperatures are reduced. Paraffin solvents or dispersants, heating, or mechanical cutting remove it from the tubing and piping. Paraffin solvents, dispersants, and hot treatment fluids are normally handled and treated as part of the crude stream in the field processing facilities. However, paraffin cut with downhole tools is generated at the wellhead.

3.5.2.3 Stuffing Box

Oil and produced water contaminated soils and debris may result from leaks in the stuffing box of a pumping unit or from minor amounts of spillage during well chemical treatment, workover, or servicing operations. The stuffing box on a pumping well is the mechanical seal between the tubing and polished rod. The fluid (for example, crude oil) being pumped acts as the seal lubricant. Because of the continuous wearing action of the polished rod, the stuffing box packing requires periodic adjustment to minimize leakage.

Pumping unit gear box lubricating oil must be replaced occasionally, either because of gear box malfunction or for pre- ventive maintenance.

3.5.2.4 Flow Lines

Flow lines gather produced fluids from wells for transport to field facilities for processing. Periodically, flow lines gathering crude production can plug from a buildup of paraffin and scale. When this occurs, either pipeline pigs are run through the flow lines or hot oil is pumped through them to remove or dissolve the plugging material.

Plugging material that is not dissolved back into the crude oil is recovered at a pig trap at the facility inlet. Recovered paraffin solids can be heated and returned to the production system or hauled to a storage site for future reclaiming or disposal. Scale material is also collected for disposal.

Flow line ruptures or leaks generate crude oil and/or produced water-contaminated soil. Depending on the severity and location of the release, contaminated soils may either be managed in situ or removed for treatment or disposal, either onsite or offsite.



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3.5.2.5 Chemical Treating

Treating chemicals such as corrosion inhibitors are sometimes injected into the well or flowline to provide protection. Chemical injection pumps typically dispense chemicals from 55-gallon drums or bulk containers. Leaks from this process may result in chemical-contaminated soils; spills should be minimized via drip pans. Any spill should be managed as described in the preceding paragraph, provided it is also in accordance with applicable state and RCRA regulations (see Section 4).

3.5.3 Oil and Produced Water Treatment Systems


When produced fluids and solids reach the field facilities, they enter the treatment system. There the gas, crude, water, and solids are separated into individual streams. Each stream is then further treated in preparation for sale or disposal, as applicable.

3.5.3.2 Free-Water Knockout

Typically, the free-water knockout (FWKO) is the first ves- sel to receive produced fluids. The FWKO separates free water (that is, water not linked to oil in an emulsion) from other produced fluids and solids. Separated produced water then flows into the water treatment system for either disposal or reinjec- tion. Periodically, solids and bottom sludges are removed from the FWKO for reclamation, treatment, or disposal.

3.5.3.3 Separators

Two-phase separators isolate produced liquids from gases as they flow from the wells. Three-phase separators, which have additional float mechanisms, also separate produced water from produced fluids. The gas, oil or condensate, and water are then further processed prior to sale or disposal. The primary waste generated by the separator consists of produced sand, scale, and bottom sludges recovered during cleanout operations.

3.5.3.4 Heater TreaterdElectrostatic Treaters

Heater treaters and/or electrostatic treaters separate emul- sified oil and water. Occasionally, emulsions (that is, bad oil) that cannot be treated successfully in a single pass through the treatment system must be placed in a standby oil tank for recycling and further treatment. Produced water separated in the treaters goes to a disposal or injection system. As is the case with the FWKO and other production vessels, these treaters are occasionally drained to remove solids and bottom sludges. Treaters that use hay or excelsior sections to absorb minute amounts of oil must be cleaned out periodically, and the absorption material must be replaced.

3.5.3.5 Desanders

Where produced water carries excessive solids (produced sand), desanders may be utilized to remove these solids. Typ- ically, much of the produced sand is also removed in other treating vessels.

3.5.3.6 Produced Water Treating Equipment

Several types of produced water treating equipment are used to prepare the water for discharge, injection, or other options. Skim tanks, gun barrels, and corrugated plate interceptors (CPIs) rely on gravity and residence time to remove residual free oil and solids from produced water. Recovered oil may be returned to the oil treating system or recycled offsite.

Another type of treatment system utilizes gas flotation. These units are used to remove small concentrations of insol- uble oil and grease from produced water. The units agitate the water by injecting a gas, usually natural gas or air, through the liquid stream. This action flocculates the sus- pended oil, grease, and dirt. The flocculated materials then rise to the surface, where they are skimmed off. This material may also be recovered as oil (for example, returned to the oil treating system).

3.5.3.7 Produced Water Tanks

Produced water tanks may be required to provide storage and additional settling time for sandsolids removal prior to discharge, injection, or other disposal. These tanks must be cleaned occasionally to remove bottoms, including oily sand and solids.

3.5.3.8 Produced Water Discharges to Surface Water

Produced water that is separated from oil and gas may be of sufficient quality to discharge after the above treatment. However, in certain instances, pits or additional tanks are used to separate additional solids and oil from the produced water prior to discharge. Bottoms or sludges are generated if solids are recovered from the settling pit or tank.

3.5.4 Dehydration and Sweetening

Field dehydration and sweetening units perform the same function as that described in greater detail for gas plants in 3.5.2 and 3.5.3. Wastes may include iron sponge, spent glycol, spent amine, spent caustic, and filters and filter media, depending on the type of system operated.

3.5.5 Injection Operations


Injection operations at field production facilities are used to either dispose of produced water or to enhance recovery of crude oil from the reservoir.



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3.5.5.2 Disposal

After initial treatment of produced water, as described above, filtering is frequently used to improve water quality before injection. Filter media must be replaced on a periodic basis; if they are permanent, they must be backwashed.

Replaceable filters include sock, cartridge, or canister units. Permanent filters may use diatomaceous earth or gran- ular media such as sand or coal. Permanent filters are periodically backwashed with fresh or produced water, which sometimes contains a small amount of surfactant.

Backwash should be circulated to a solids treatment and disposal system. There, backwash liquid should be returned to the production facilities for reprocessing.

After filtering, produced water can be injected into the disposal well. An electric motor or gas engine usually drives the injection pump, pressurizing produced water into the injection well. Waste lubricating oil and filters are typically generated at these facilities.

3.5.5.3 Enhanced Recovery

Enhanced recovery is used to maintain pressures in the reservoir and to improve recovery of crude oil from reservoir formations. Several methods of enhanced recovery may be used; these include produced water injection, source water injection, seawater injection, steam flooding, or CO, flooding. Although these methods are most common, other methods are also available. The method selected will be dictated by the formation type and method feasibility.

As with injection disposal, water utilized for enhanced recovery must be treated prior to injection. In general, the types of equipment used and the wastes generated are the same as described above.

3.5.5.4 TEOR Steam Generators

In heavy oil operations, steam is sometimes injected into reservoirs to reduce oil viscosity and to enhance fluid production. Traditionally, oilfield operators have generated steam using conventionally fired heaters known as thermally enhanced oil recovery (TEOR) steam generators. The steam these generators make is injected into geological formations containing heavy crude oil; it heats the oil for easier recovery. Injected steam also drives (or pushes) the oil toward producing wells.

TEOR steam generators are fueled by either crude oil, fuel oil, or natural gas. Steam generators fired by crude or fuel oil may have sulfur dioxide air pollution scrubbers associated with them. Steam is also generated and used in some field production facilities and gas plants by burning natural gas.

When burning crude, fly ash impinges on the steam generator convection tubes. To increase thermal efficiency of the generators, fly ash is removed by washing the tubes with water. The resulting effluent is referred to as stack wash water.

Other wastes from steam generators can include fuel oil filters, spent water softening resin, refractory waste, and flue duct ash. Water softening resin is typically used when a central water plant is not available.

3.5.5.5 TEOR Cogeneration Units

Recently, TEOR cogeneration steam generators have replaced some TEOR conventional steam generators. Typi- cally, a TEOR cogeneration steam generator consists of a turbine and its associated heat recovery boilers (steam generators). Cogeneration of electricity and steam can signifi- cantly increase the energy efficiency of the process.

TEOR steam generators use soft water (that is, water with low concentrations of dissolved calcium and magnesium). Soft water is used as steam generator feed water to prevent scaling. The water softening process creates a waste fluid identified as regeneration brine. Surplus soft water for disposal (that is, soft water blowdown) is also generated during startup and shutdown of both conventional and cogeneration steam generators.

Waste fluids typically generated at TEOR facilities consist of water softener generation brine, surplus soft water (for example, soft water blowdown), excess deionized water, backwash water from the deionization process, scrubber waste (that is, sulfur dioxide liquor), and stack wash.

A typical waste generated at facilities using steam is boiler blowdown water.

3.5.5.6 Air Pollution Control Scrubbers

Air pollution control scrubbers may be required to control sulfur dioxide and particulate matter emissions from exhaust gases of oil-fired TEOR steam generators. The process bub- bles exhaust gas through a basic aqueous solution (usually NaOH or Na2C0,) which reduces SO, to NaHSO,, Na,SO,, and Na2S04. The scrubber liquor waste typically has a neu- tral pH and low concentration of heavy metals.

3.5.5.7 Deionization

Two other fluids associated only with TEOR cogeneration plants are deionized water and backwash produced from the water purification process. The deionization process involves removing additional dissolved minerals present in water. Deionized water is injected into the turbine combustion chamber to reduce nitrogen oxide emissions. Raw water used in the deionization process is either soft water or fresh water.

Excess deionization water, as well as backwash from this water purification process, may be commingled with excess produced water, regeneration brine, and soft water blowdown prior to disposal.



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3.5.6 Oil Storage and Sales

Treated oil that leaves the treatment system goes to oil stock tanks and is ready for sale. Solids and water continue to separate by gravity and accumulate in stock tanks. These tank bottom materials may require periodic removal.

Oil in stock tanks is transported offsite for further processing or refining via pipeline, tank truck, or barge. Wastes generated from onsite transfer operations include lubrication oils, filters, and drips and leaks from pumps and transfer lines. When shipping by tank truck or barge, drainage from transfer hoses can be returned to the system for reprocessing.

3.5.7 Compression and Gas Sales


Produced gas and fuel scrubbers are used where necessary to separate fluids from gas. After scrubbing, recovered fluids may include condensate, oil, and/or produced waters; these should be returned to the system for reprocessing.

3.5.7.2 Hydrate Prevention

Pressure and temperature decrease as gas is produced from a reservoir. If sufficient water or water vapor exists in the gas stream, hydrates (that is, ice) may form and block flow lines. Methanol is sometimes injected or line heaters are sometimes used to prevent hydrate formation. Methanol is typically used in low concentrations; the concentrations are dictated by field conditions.

The primary waste generated onsite from methanol injection is empty methanol containers. Wastes generated from line heaters include spent thermal fluids (such as glycol, oil, or salt mixtures) used to transfer heat from heat sources to the gas stream.

3.5.7.3 Compressors

Compressors are used to boost the gas pressure to sales line pressure and/or gas lift pressure, inject gas back into the reservoir for pressure maintenance, permit vapor recovery, or allow flow into central facilities. Compressors may be driven by electric motors or by internal combustion or turbine en- gines.

Wastes generated from compressor operation are identical to those wastes generated by gas plant compressors (see 3.6.2 and 3.6.6). These include engine cooling water containing glycol and used lubrication oil and filters.

3.5.8 Other Field Production Facilities and Operations

Heat exchangers, glycol systems, absorption oil systems, storage tanks, and the like must be cleaned to remove hydrocarbons, salts, scale, and other solids that have built up and reduced field production efficiency.

Internal cleaning of tanks, treating and process vessels, and other equipment is also an operation that can generate wastes.

Wastes generated during cleaning include mixtures of spent cleaning solutions (for example, acids, caustics, solvents, and detergents) and removed solids and/or hydrocarbons.

Other field production facilities or operations that may generate waste include the following:

a. Warehousing. b. Equipment maintenance. c. Domestic and sanitary waste handling and treating. d. Construction and demolition. e. Laboratory testing. f. Office, transportation, and maintenance facilities.

3.5.9 Waste Summary

A list of major categories of waste that can be generated during field production operations is shown below. (Note that some of these wastes may be contaminated with naturally occurring radioactive material (NORM) and require special handling.) See Appendix C for a more complete listing of wastes generated by E&P.

Field Production Operations Waste

Absorbent material Antifreeze

Batteries Blasting sand/material Boiler blowdown

Catalyst Cleaning wastes, process

equipment

fluids Completion/W.O./well treatment

Constructioddemolition debris Cooling tower blowdown

Crude oikondensate, waste Deionized water, excess

Domestic refuse Domestic wastewater

Filters Flue dust ash (fly ash) first-aid waste

Hydraulic fluid Incineration ash Insulation material Lab waste, sample wastes, and

residues Mercury, metallic liquid Mercury, solids Naturally occurring radioactive

material (NORM)

Pipe/equipment scale Pit sludges Polychlorinated biphenyls (PCBs) Produced sand Produced water

Rags, oily Refractory waste

Saltbath heater salt

Sanitary wastewater

Scrap metal Scrubber liquid, hydrogen sulfide

Soft water, excess

Soil, contaminated Solvents Source sand

Source water

Spill cleanup waste, hydrocarbon

Storm water Sulfur dioxide liquor Sweeteningldehydration liquids Sweetening/dehydration solids

(for example, crude)

Tank bottoms Tires Unused materials, discarded



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Packing fluids Used oil Paint-Elated materials Vegetation Pallets Washdown water (rigwash) Paraffin Water, noncontact (for example,

Pigging wastes from gathering Water softener regeneration brine cooling or fire water)

lines

Pigging wastes from DOT Water softening resin, spent

Fipdequipment hydrates Wood

3.6 GAS PLANT OPERATIONS

3.6.1 Introduction

pipelines

Natural gas plants often provide dehydration and compression facilities; sometimes sweetening facilities are provided as well. These plants process natural gas into a marketable condition; they also extract natural gas liquids such as ethane, propane, and butane for separate sale. Natu- ral gas streams entering gas processing plants vary in com- position. Methane is the predominant component, but smaller amounts of ethane, propane, butane, pentane, and heavier hydrocarbons are also present. The inlet gas may contain compounds such as carbon dioxide, hydrogen sulfide, mercaptans, other sulfur compounds, water, and certain solid impurities. These can be removed by gas plant treating facilities. Treated gas then enters an extraction facility that removes the heavier natural gas liquids (NGLs) such as ethane, propane, and butane.

Gas plant treating and extraction processes include inlet separation and compression, dehydration, sweeteninghlfur recovery, natural gas liquids recovery, and recompression and plant utilities. Warehousing, product storage, equipment maintenance, domestic and sanitary waste handling and treating, construction and demolition, product shipping, and office facilities are other activities that can occur at a gas plant and generate wastes.

3.6.2 Inlet Separation and Compression

Gas can enter the facility in either an untreated or treated condition. Field production facilities can provide initial treatment; all subsequent treatment, however, is conducted at the gas plant. Produced fluids such as water and liquid hydrocarbons are usually separated at the plant inlet. If necessary, gas will be compressed to a sufficient pressure to allow the plant to operate.

Wastes typically associated with inlet separation include produced water that may contain methanol or other treating chemicals; pigging materials; inlet filter media; fluids from corrosion treatments; and small amounts of solid material (such as, pipe scale, rust, and reservoir formation material).

Wastes generated from plant inlet compressor operations are like wastes generated in field compressor operations.

These include engine cooling water containing glycol and used lubrication oil and filters.

Inlet separators are designed to send produced water and hydrocarbons to process vessels for additional treatment. There, hydrocarbons can be recovered for sale and produced water can be separated for disposal.

Small amounts of pigging materials can also be recovered at the pig receiving traps at the plant inlet.

For safety reasons, inlet separators are equipped with re- lief valves that vent to emergency containment facilities, that are usually pits. This protects the facility if a fluid slug (for example, produced water) that exceeds separator capacity should reach the plant or if gas pressure exceeds design capacity.

Emergency pits are not disposal facilities; they provide control of emergency releases. Vented fluids should be recovered in accordance with state requirements or operating procedures. The pits should be constructed and operated to prevent groundwater contamination.

3.6.3 Dehydration

All natural gas contains water vapor. Typically, this water content must be reduced to meet sales pipeline specifica- tions. Dehydration is the process of extracting water vapor to make the gas marketable. Processes used at gas plants are like those used at field production facilities where central- ized dehydration is unavailable.

Natural gas is dehydrated by contact with either liquid or solid desiccants.

Liquid desiccants such as ethylene glycol, diethylene glycol, or triethylene glycol absorb the water. Heat regeneration evaporates the water, and glycol is recovered for reuse.

In solid desiccant dehydration, natural gas flows through tower vessels filled with alumina, silica-gel, silica-alumina beads, or a molecular sieve to absorb water vapor.

Wastes generated du

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6. API E5 (1)